Aural motor knock detector



J. C. SEBER I AURAL MOTOR KNOG'K DETECTOR Aug. 26, 1930.

Filed Oct. 10, 1927 VINVENTOIR.

WITNESSES Patented Aug. 26, 1930 UNITED STATES PATENT OFFICE AURAL MOTOR-KNOCK DETECTOR Application filed October 10, 1927. Serial No. 225,131.

My invention relates to improvements in aural motor knock detectors, for use in private or public garages, repair shops, machine shops, motor vehicle plants; and the various mamifacturing plants and industries, where internal combustion motors and engines are constructed or utilized; where it is essential to have quick accurate means of detecting the specific cylinder in which the integral parts are defective or not properly fitted to place, to function properly, thereby causlng what is commonly known to the trade as motor-knock.

My invention is particularly adapted to that type of internal combustion motors in which four or more cylinders are combined, on one bed, to generate the required horsepower and speed, so extensively utilized and marketed in the automobile and motor vehicle industries.

The object of my invention is to provide, at a minimum of cost, a dependable accurate aural motor-knock detector, which will enable the mechanic to locate, in a minimum of time, the specific cylinder in the motor and the defective part therein, to which the motonknock is traceable.

Further objects and advantages will appear in the following description; it being ui'iderstood that various changes in the form,

proportions, and minor details of construction may be resorted to within the scope of the appended claims.

In the drawings hereto attached and made part hereof, Figure 1 is a side view showing the general appearance of my combination device, with the parts assembled in position forming my aural motor-knock detector complete.

Fig. 2 is a cross section view full length in which the parts are assembled as in Fig. 1, showing the relative position of each in combination.

Fig. 3 is a top view of the sensitive resonant metal unit of the device.

Similar numerals refer to similar parts throughout the several views. The tubular opening 1 extending the entire length of the resonant metal unit; the machined base section 2 which is inserted in spark plug hole in motor head; the standard threaded section 2% fitted to spark plug tap in motor head to hold devlce 1n position for test; the grooved section t; the enlarged flange section 5 which rests on motor head; the grooved section 6; the enlarged section 7 forming hexagon nut to screw unit in position on motor head; the tapered section 8 to which the hose is attached, the heavy ribbed insulated hose unit 9; the ribbed outer insulation of hose eo 10; the intermediate layer of fibrous filling 11 impervious to external sound; the inner insulation of hose 12; the tubular opening extending full length of hose 13 through which the distinctive sounds of defective parts are conveyed to the ear of the operator during the tests.

In my aural motor-knock detector device, I accomplish the objects set forth by using in combination; a hollow metal sound registering device, constructed out of suitable metal, bronze, bell-metal or steel; preferably using a special brand of high grade sixty point carbon steel, selected for its sensitive conducive resonance. The said device being .75 molded or forged in one piece, and machined to a special ti'iickness of shape and form, having-a tubular o Jening in the center, extei'iding the full length, the same being machined in assorted sizes to meet the re quirements of the trade, and being threaded to fit the several standard spark plug threads tapped in motor heads. The lower end or base portion, being machined to a size permitting its insertion in the spark plug hole in motor head, for a distance of SGVG11-S1Xt6011tl1S of an inch. At a point beginning seven-sixteenths of an inch from the bottom or base end, a standard thread is cut, extending for a distance of threc-eighths of an inch, to fit the spark plug threads in motor head. Above the threaded portion a. one-eighth inch groove is cut, beneath an enlarged section or flange three-sixteenths of an inch thick, forming a shoulder, which when screwed to position fits tight to flat surface on motor head. Above this flange a one-eighth inch groove is cut beneath an enlarged section, which is machined having faces three-eighths of an inch wide and onehalf inch in height, positioned to form av seyen-eighths inch hexagon nut, utilized in screwing the device in position on the motor head. The upper section of the resonant metal unit, for a distance of one and onehalf inches is machined on a taper, to facilitate the fitting of the insulated ribbed hose used in combination with the metal unit in registering the sounds oi the defective cylinder parts, and conveying the same clearly and distinctly to the operators car, at the open end of hose.

In testing each cylinder, with my aural DXO'QOY-liHOCk detector, the spark plug is remorcd first. Then the special resonant steel unit is screwed in place on the motor head; and the special insulated ribbed hose, used in combination with the same, is piaced in position on the apered end at top. After starting the motor, the operator by extend ing the hose, and standing from live to eight feet from the open end of hose is enabled to detect the sound of each integral part, and locate instantly the defect. The resonance of the steel and the insulation oi. the hose combined, forming a perfect register of the distinct sound of each part, which is not functioning properly.

In making primary tests with my device, I used a hose section of suilicient length to extend through the wall outside of the garage, thinking the noise of the active cylinders, during the test might interfere with a successful outcome. I have since proved in numerous tests, that a short length oi. the special hose will register clearly and distinctly, close to the motor being tested by my combination device.

I claim:

1. An aural motor knock detector, comprising a. tubular member, composed of a cover and a lining, and a liller therebetween to cooperate with said cover and lining, and means for connecting said tubular member directly with the motor.

An aural motor knock detector, comprising a tubular member, composed of a cover and a lining, and a filler of fibrous material therebetween to cooperate with said cover and lining, and means for connecting said tubular member directly with the motor.

In testimony whereof I hereunto allix my signature.

/ JACOB CHRISTOPHER SEBER. 

